Literally everything you said can be applied to about 95% of mid laners.
{quoted} Predictable - All of his moves are telgraphed and can be seen from a mile away.
Tell me one mid laner who doesn't have highly telegraphed attacks (except Annie and LeBlanc because they're special snowflakes).
Damage - Most of his burst damage is loaded into his ult. Which is literally the easiest thing in the world to avoid, because you have 4 seconds to see it coming. Without his ult, his damage isn't particularly special for an assassin.
Really? Veigar, Lux, Syndra, Annie, Malz, Lissandra, Viktor, Vel'Koz. Every single one of them rely on their ult to burst someone down - and with the exception of Lissandra, none of them have a single "oh shit I dun goofed better get away scott free" button.
Harass - He has no actual sustain in lane, and his Q chews through his mana if he uses it to farm. Constantly poke him and make him b whenever possible.
Once again, almost no mid laners lack sustain. Veigar, Lux, Malz (barring his E, which still doesn't make up for his ridiculous mana costs), Viktor, Orianna, Vel'Koz. Lux's and Viktor's E in particular cost a staggering 130 mana to cast at max rank, and Veigar needs to expend at least 210 mana to do any real damage - and even then, relies on the enemy screwing up. Ekko by comparison can spam whatever the hell he likes because his mana costs aren't sky-high, and he never has to worry about not having mana for his Ultimate.
4People who fight back - Ekko thrives on your fear. He lives to know that if he engages, you're going to turn tail and run. Don't give him that satisfaction. Any champion that can turn a fight around on Ekko will absolutely destroy him. To name a few mid lane examples: Zyra, Viktor, Swain, Mordekaiser, Lissandra, and Diana.
So what you're telling me is "don't go in when the enemy has everything up"? Great advice. Shame that's not unique to Ekko. But it's ok. The fact that Ekko can outdamage, out CC and outmaneuver everyone is fine. As long as he makes flashy plays, right?
Don't worry, I'll help you. One of the burdens of intelligence, but ah well, such is my fate.
Oh, and just so you know, that makes you sound like a major snob.